Template parts in Wordpress - Performance & Optimization

Performance: Template parts

MEDIUM IMPACT

Template parts affect page load speed by controlling how reusable sections of a page are loaded and rendered.

Including reusable page sections in a WordPress theme

Wordpress

<?php
ob_start();
get_template_part('header');
$header_html = ob_get_clean();
echo $header_html;
echo $header_html;
echo $header_html;
?>

Load the template part once, store output, and reuse it to avoid repeated file reads and processing.

📈 Performance GainSingle file read and PHP execution, reducing server load and improving LCP.

Including reusable page sections in a WordPress theme

Wordpress

<?php get_template_part('header'); ?>
<?php get_template_part('header'); ?>
<?php get_template_part('header'); ?>

Calling the same template part multiple times causes repeated file reads and PHP processing, slowing page generation.

📉 Performance CostTriggers multiple file system reads and PHP executions, increasing server response time.

Performance Comparison

Pattern	DOM Operations	Reflows	Paint Cost	Verdict
Repeated get_template_part calls	No extra DOM nodes but slower HTML generation	No direct reflows but delayed HTML delivery	Normal paint cost	[X] Bad
Single get_template_part call with output reuse	No extra DOM nodes, faster HTML generation	No reflows, faster HTML delivery	Normal paint cost	[OK] Good

Rendering Pipeline

Template parts are processed by PHP on the server before sending HTML to the browser. Efficient use reduces server processing and speeds up HTML delivery.

→Server-side PHP processing

→HTML generation

→Browser rendering

⚠️ BottleneckServer-side PHP file inclusion and processing

Core Web Vital Affected

LCP

Template parts affect page load speed by controlling how reusable sections of a page are loaded and rendered.

Optimization Tips

1Avoid calling get_template_part multiple times for the same content without caching.

2Cache or store template part output if reused multiple times on a page.

3Efficient template part usage improves server response and LCP.

Performance Quiz - 3 Questions

What is a performance downside of calling get_template_part multiple times for the same part?

A It increases CSS selector complexity

B Repeated file reads and PHP processing slow server response

C It causes extra DOM nodes in the browser

D It triggers layout shifts in the browser

DevTools: Network

How to check: Open DevTools, go to Network tab, reload page, and check server response time and HTML size.

What to look for: Look for faster server response and smaller HTML size indicating efficient template part usage.